Salts Abbreviation HBD Molar ratio Symbol
Methyltriphenylphosphonium bromide MTPB TEG 1:4 DES1[13]
Methyltriphenylphosphonium bromide MTPB DEG 1:4 DES2
Methyltriphenylphosphonium bromide MTPB EG 1:4 DES3
Methyltriphenylphosphonium bromide MTPB GL 1:4 DES4
Table 1: Composition and abbreviation of DESs used in this research.